US 6,151,569 AGranted

Automated sequence of machine-performed attempts to unfreeze an apparently frozen application program

AssigneeSymantec Corporation

InventorScott Elliott

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Abstract

An apparatus and computer method, that are generally referred to herein as ANTI-FREEZE.TM., are provided for controlling the operation of a computer running under a multitasking operating system (OS) such as WINDOWS.RTM. 95 or WINDOWS.RTM. NT operating system. When an application program becomes unresponsive to inputs from the keyboard and/or mouse, ANTI-FREEZE.TM. provides a user interface for identifying the unresponsive program and for causing the OS to send a message to the identified program. If the identified program responds to the message, ANTI-FREEZE.TM. determines if the identified program has any disabled windows and if so, enables a a disabled window. If the identified program does not respond to the message, ANTI-FREEZE.TM. modifies the stack or another part of the identified program in a way that causes it to become responsive to messages sent from the OS.

Claims38

Dependent claims

A machine-implemented method for reestablishing user access to an apparently frozen and identified one of plural programs running under a multitasking operating system,

where said plural programs include multitasked programs;
where for each respective multitasked program running under said OS (operating system), the OS provides a respective virtual processor that includes a virtual stack and a plurality of respective context registers for supporting multitasking said context registers including an instruction pointer for keeping track of what instruction the multitasked program is next to execute when its execution resumes during multitasking, and a stack pointer for keeping track of what location in its virtual stack the multitasked program is next to reference as its top-of-stack when its execution resumes during multitasking,
where said OS further provides a standard-for-type calling function for use by each given one of the multitasked programs when that given multitasked program is about to invoke a callable, target function of a corresponding type, and
where said standard calling function consistently within said OS, places a special signature value on the virtual stack of a given program for use in returning from a respectively invoked target function of the corresponding type after the given program uses the standard-for-type calling function to invoke the respective target function;
said machine-implemented, reestablishing method comprising the steps of:
(a) determining whether the identified program is soft-locked or hard-locked, where a soft-locked program is one that responds to messages sent to it from the OS, and a hard-locked program is one that does not respond to messages sent to it from the OS;
(b) in response to said determining step (a) determining that the identified program is soft-locked, searching for a disabled window associated with the identified program and, if such a window is found, enabling the found window;
(c) in response to said determining step (a) determining that the identified program is hard-locked, performing at least one of the substeps of:
(c.1) searching for said special signature value on the virtual stack of the identified program;
and
(c.2) installing an external message dispatch loop for the identified program;
and
(d) in further response to said determining step (a) determining that the identified program is hard-locked, and after one of said substeps (c.1) and (c.2) is performed, modifying at least one of the context registers of the identified program and initiating multitasked execution of the identified program with the modified, at least one context register.

10 more elements

A computing machine having a multitasking operating system (OS) and an ability to unfreeze an identified one of multitasked programs running under the multitasking operating system,

wherein for each respective multitasked program running under said OS, the OS provides a respective virtual processor that includes a virtual stack and a plurality of respective context registers for supporting multitasking, said context registers including an instruction pointer for keeping track of what instruction the multitasked program is next to execute when its execution resumes during multitasking, and a stack pointer for keeping track of what location in its virtual stack the multitasked program is next to reference as its top-of-stack when its execution resumes during multitasking,
wherein said OS further provides a standard-for-type invoking function for use by each given one of the multitasked programs when that given multitasked program is about to invoke a target function of a corresponding type,
where said standard-for-type invoking function consistently within said OS, places a special signature on the virtual stack of the given program that uses said standard-for-type invoking function to respectively invoke a given target function of the corresponding type;
and
said OS manipulates windows within window trees, including passing messages to selected ones of said windows;
said computing machine comprising:
(a) determining means for determining whether the identified program is soft-locked or hard-locked, where a soft-locked program is one that responds to messages sent to it from the OS, and a hard-locked program is one that does not respond to messages sent to it from the OS;
(b) first unfreezing means, responsive to said determining means such that when said determining means determines the identified program is soft-locked, the first unfreezing means searches for a disabled window associated with the identified program and, if such a window is found, enables the found window;
(c) second unfreezing means, responsive to said determining means such that when said determining means determines the identified program is hard-locked, the second unfreezing means performs at least one of the substeps of:
(c.1 ) searching for said special signature value on the virtual stack of the identified program;
and
(c.2) installing an external message dispatch loop for the identified program;
and
wherein after one of said substeps (c.1) and (c.2) is performed by the second unfreezing means , said second unfreezing means further modifies at least one of the context registers of the identified program and initiates multitasked execution of the identified program with the modified, at least one context register.

11 more elements

A manufactured, instructing signal for instructing a predefined computing machine to perform an unfreezing operation on an identified program, where the computing machine has a multitasking operating system (OS) and the identified program is one of plural multitasked programs running under the multitasking operating system,

wherein for each respective multitasked program running under said OS, the OS provides a respective virtual processor that includes a virtual stack and a plurality of respective context registers for supporting multitasking, said context registers including an instruction pointer for keeping track of what instruction the multitasked program is next to execute when its execution resumes during multitasking, and a stack pointer for keeping track of what location in its virtual stack the multitasked program is next to reference as its top-of-stack when its execution resumes during multitasking,
wherein said OS further provides a standard-for-type invoking function for use by each given one of the multitasked programs when that given multitasked program is about to invoke a target function of a corresponding type,
where said standard-for-type invoking function consistently within said OS, places a special signature on the virtual stack of the given program that uses said standard-for-type invoking function to respectively invoke a given target function of the corresponding type;
and
said OS manipulates windows within window trees, including passing messages to selected ones of said windows;
said instructing signal instructing the computing machine to perform a set of operations comprising:
(a) determining whether the identified program is soft-locked or hard-locked, where a soft-locked program is one that responds to messages sent to it from the OS, and a hard-locked program is one that does not respond to messages sent to it from the OS;
(b) in response to said determining step (a) determining that the identified program is soft-locked, searching for a disabled window associated with the identified program and, if such a window is found, enabling the found window;
(c) in response to said determining step (a) determining that the identified program is hard-locked, performing at least one of the substeps of:
(c.1) searching for said special signature value on the virtual stack of the identified program;
and
(c.2) installing an external message dispatch loop for the identified program;
and
(d) in further response to said determining step (a) determining that the identified program is hard-locked, and after one of said substeps (c.1) and (c.2) is performed, modifying at least one of the context registers of the identified program and initiating multitasked execution of the identified program with the modified, at least one context register.

11 more elements

A computer-readable medium for instructing a predefined computing machine to perform an unfreezing operation on an identified program, where the computing machine has a multitasking operating system (OS) and the identified program is one of plural multitasked programs running under the multitasking operating system,

wherein for each respective multitasked program running under said OS, the OS provides a respective virtual processor that includes a virtual stack and a plurality of respective context registers for supporting multitasking, said context registers including an instruction pointer for keeping track of what instruction the multitasked program is next to execute when its execution resumes during multitasking, and a stack pointer for keeping track of what location in its virtual stack the multitasked program is next to reference as its top-of-stack when its execution resumes during multitasking,
wherein said OS further provides a standard-for-type invoking function for use by each given one of the multitasked programs when that given multitasked program is about to invoke a target function of a corresponding type,
where said standard-for-type invoking function consistently within said OS, places a special signature on the virtual stack of the given program that uses said standard-for-type invoking function to respectively invoke a given target function of the corresponding type;
and
said OS manipulates windows, including passing messages to selected ones of said windows;
said computer-readable medium instructing the computing machine to perform a set of operations comprising:
(a) determining whether the identified program is soft-locked or hard-locked, where a soft-locked program is one that responds to messages sent to it from the OS, and a hard-locked program is one that does not respond to messages sent to it from the OS;
(b) in response to said determining step (a) determining that the identified program is soft-locked, searching for a disabled window associated with the identified program and, if such a window is found, enabling the found window;
(c) in response to said determining step (a) determining that the identified program is hard-locked, performing at least one of the substeps of:
(c.1) searching for said special signature value on the virtual stack of the identified program;
and
(c.2) installing an external message dispatch loop for the identified program;
and
(d) in further response to said determining step (a) determining that the identified program is hard-locked, and after one of said substeps (c.1) and (c.2) is performed, modifying at least one of the context registers of the identified program and initiating multitasked execution of the identified program with the modified, at least one context register.

11 more elements

A machine-implemented method for automatically sequencing through a hierarchy of attempts to unfreeze an identified and apparently frozen application program;

wherein the apparently frozen application program executes in a computing machine having a multitasking operating system (OS);
wherein the identified program is one of plural multitasked programs running under the multitasking operating system,
wherein for each respective multitasked program running under said OS, the OS provides a respective virtual processor that includes a virtual stack and a plurality of respective context registers for supporting multitasking, said context registers including an instruction pointer for keeping track of what instruction the multitasked program is next to execute when its execution resumes during multitasking, and a stack pointer for keeping track of what location in its virtual stack the multitasked program is next to reference as its top-of-stack when its execution resumes during multitasking,
wherein said OS further provides a standard-for-type invoking function for use by each given one of the multitasked programs when that given multitasked program is about to invoke a target function of a corresponding type,
wherein said standard-for-type invoking function consistently within said OS, places a special signature on the virtual stack of the given program that uses said standard-for-type invoking function to respectively invoke a given target function of the corresponding type;
and
wherein said OS manipulates windows, including passing messages to selected ones of said windows;
said machine-implemented method for automatically sequencing through the hierarchy of attempts comprising the steps of:
(a) determining whether the identified program is soft-locked or hard-locked, where a soft-locked program is one that responds to messages sent to it from the OS, and a hard-locked program is one that does not respond to messages sent to it from the OS;
(b) in response to said determining step (a) determining that the identified program is soft-locked, searching for a disabled window associated with the identified program and, if at least one such a window is found, enabling the found window;
(c) in response to said determining step (a) determining that the identified program is hard-locked, searching for said special signature on the virtual stack of the identified program;
and
(d) if said step (c) of searching for the special signature is unsuccessful, establishing an external message dispatch loop for the identified program.

10 more elements

Dependencies are inferred from the claim text.